1. Field of the Invention
The present invention is directed to energy recovery fluid motors and, more particularly, to a fluid motor wherein a high pressure, saturated or near saturated liquid changes phase during an expansion power stroke, which is after a hydraulic power stroke and before exhausting from the motor.
2. Description of the Prior Art
Various fluid circuits, especially refrigeration and/or heating systems, include segments where a higher pressure liquid is throttled through a valve to a lower pressure reservoir. In an absorption refrigeration system, for example, a higher pressure liquid passes through a control valve to a lower pressure evaporator. The evaporator absorbs heat from the environment thereby refrigerating the environment as desired. As the liquid is throttled through the valve, it at least partially changes phase. There is a loss not only of flow energy due to the pressure decrease through the valve, but also a loss of energy to the liquid when it changes phase from a liquid to a gas. The present invention is directed to convert some of the otherwise lost energy to mechanical energy.